Joint lock mechanism for digging cap of excavating tooth assemblies



Sept. 16, 1952 CRAWFORD 2,610,416

JOINT LOCK MECHANISM FOR DIGGING CAP OF EXCAVATING TOOTH ASSEMBLIES Filed Sept. 17, 1948 ids: 1.

\ INVENTOR.

' flrfbur MC'rawfbz-d HTTYS Patented Sept. 16, 1952 7 asides JorNT LOCKMECH'ANISMVFOR procure oAr or sxcavrrrmc 'roorrn ASSEMBLIES v I Arthur Crawford, Baker, Oreg.

, idpplicationseptember 17,1948, scram. 49,705

' bucket, or the like,-the tooth assembly being of the type which includes a replaceable tooth and an initially separate adapter by" means of the tooth is rigidly mounted in place. in the lip of a bucket.

Another object of the present invention is to providea tooth assembly, as above, which includes an improved releasable locking device between the tooth and adapter; such locking device being designed for ease of placement, and yet when in use securing the tooth and adapter against accidental separation.

A further object of the invention is to provide a tooth assembly, as in the preceding paragraph, in which the locking device includes a transverse key adapted to extend through interengaged parts of the tooth and adapter in driveout relation; said key being spring-pressed laterally to normally hold the same in place.

An additional object of the invention is to provide a tooth assembly which is designed for ready and economical manufacture.

A further object of the invention is to provide a practical and reliable tooth assembly, and one which will be exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claim.

In the drawings:

Fig. 1 is a side elevation of the tooth assembly showing the tooth and adapter in their relative positions, but separated.

Fig. 2 is a side elevation of the tooth assembly with the tooth and adapter as locked in engagement.

Fig. 3 is a rear end view of the tooth, detached.

Fig. 4 is a sectional plan on line 4-4 of Fig. 2.

Referring now more particularly to the characters of reference on the drawings, the tooth assembly comprises a base or adapter, indicated generally at l, which adapter includes a body 2 arranged to be affixed to the cutting lip of the bucket of a power shovel, dredge, or the like in forwardly projecting relation. The means for attaching the adapter to the bucket lip is not here shown, and may be conventional.

At its forward end the body integral relation, a forwardly projecting tongue 3, which tongue is parallel-sided and'tapers in a vertical plane.

1 claim. (or. 31-442) which The taper tongue 3 is generally symmetrical atflits innerend to thefadjacent portion of the bcdyl, but is of "somewhat'smaller'cross section, whereby toprovide stop shoulders 4 on said body all about the tongue. I The numeral 5'indicatesgenerallya removable tooth having a rigid} point 5 at the frontand a tapered socket I whichopens, rearwardly. The socket l is adapted to receive the taper tongue 3 in close matching relation, with the rear edges 8 of the socket l in abutment with the stop shoulders 4. s

Additionally'the tooth 5 includes, at the rear, and adjacent the upper portion thereof, apair of transversely spaced lugs "9 which project rear wardly for engagement in corresponding, for- 2 includes, in

wardly opening notches W in opposite sides of the body 2 of adapter I.

The arrangement of the lugs 9 and notches l0 serves to reduce the strain on the tongue 3 when the tooth assembly is in use. This strain is further minimized by upwardly facing, locator ledges H formed on the sides l2 of socket I internally and adjacent the bottom corner thereof. The 10- cator ledges II are received in matching cutaway portions I3 on opposite sides of the tongue; the downwardly facing shoulders 13a formed by said cut-away portions riding directly on top of the locator ledges l I when the tooth assembly is in use. 7

When the tooth 5 is mounted on the adapter I by engagement of the tongue 3 in socket I, such parts are releasably but normally secured against separation by the following locking device.

Intermediate its ends the tongue 3 is formed with a transverse key slot l4, and a pair of transversely spaced, longitudinally extending, heavyduty compression springs l5 work into said slot from forwardly projecting pockets cr recesses it in communication with the latter.

As'will be noted from Fig. 1, the diameter of springs l5, and the height of their recesses It, is greater than the height of the key slot I4. It will also be noted that such recesses out into the forward side of slot l4 only sufficient to allow the springs to expand into the path of the key while preventing the springs from blocking said path.

Above the locator ledges l l, the sides [2 of the socket I include key slots H, which register with the key slot 14 when the tongue 3 is engaged in the socket 1.

The key slots l4 and H are rectangular in cross section, as shown. A transverse key 18, similarly rectangular in cross section, but capable of engagement through the key slots I4 and IT, is disposed therein with a relatively tight but 3 drive-out fit. When the key I8 is in working position in the key slots I 4 and 11, the springs l5 are loaded and bear against the forward edge of said key, whereby to normally hold the same against accidental displacement laterally of the tooth assembly.

The key I8, when in use, is of a length substantially equal to the width of the socket I, but

said key is initially formed with a tapered guide point I9 to facilitate initial entry of the key through the slots I4 and H. The key is initially transversely scored, as at 20, at the innerend of the guide point 19 whereby, after the key'is in place, said guide point can be broken off by the blow of a hammer.

With the described arrangementthe tooth 5 is normally rigidly, but removably, mounted on the adapter I; the mounting being stable and effective. However, when it is desired to remove the tooth 5 for the purpose of repair or replacement, it is only necessary-to drive out the transverse key- I8, whereupon the parts may be readily separated From the'foregoing description it will be readily seen that there has been produced such a device as substantially fulfills the objects of the invention, as set forth herein. 7

While this specification sets forth in detail the adapter having a forwardly projecting tongue, a tooth having a rearwardly open socket to fit over the tongue, the tongue and the sides of the socket having transverse key slots adapted to register when the tooth is mounted on the tongue, a key adapted to be removably driven through the slots, said key having a lateral taper at its forward end, the tongue having a longitudinal recess cut in each side thereof and extending forwardly from the forward side of the tongue slot, the height of the recess being greater than the height of the slot and said recess cutting across the slot from said forward side thereof for a short portion of the width of said slot, and a compression spring fitting and countersunk in each recess and when expanded before placement of the key engaging both ends of the associated recess so as to then project into the path of the present and preferred construction of the device,

still in practice such deviationsfrom such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appendedclaim. Having thus described theinvention, the following is claimed as new and useful, and upon which Letters Patent are desired:

A tooth "assembly for-buckets comprising an key for contraction thereby when said key is driven through the slots.

' Y .ARTHUR N. CRAWFORD. REFERENCES CITED The 'followingreferences are of record in the file of this patent:

UNITED STATES PATENTS Eaton 1 Apr. 5, 

